1. Field of the Invention
The present invention relates to optics and, more particularly, to a collimating and beam-shaping element. The element of the present invention is particularly suitable for use with laser diodes.
2. Description Relative to the Prior Art
Laser diodes have become a preferred light source for a wide variety of modern day applications. Many of these applications require collimation and rectification. As used herein, collimation means conversion of divergent radiation into a parallel beam, which can subsequently be reshaped at a distance in a variety of optical systems (such as scanners and compact disc players). Rectification, as used herein, means the circularizing of the beam symmetry so that the focus of points of equal intensity form a circle Laser diodes typically have elliptical radiation patterns, i.e., different divergence in planes parallel and perpendicular to the diode junction. Anamorphic optical systems have been described to accomplish rectification by means of cylindrical lenses or refracting prisms. In addition, the natural astigmatism of the diode source requires correction. This can be accomplished by a weak cylindrical lens.
If conventional design and fabrication methods are utilized, satisfying all of the foregoing criteria requires a multi-element optical system which increases size, weight, cost, and assembly difficulties.